RadioBanter - View Single Post

wrote:
Since posting earlier I've been on to the actual manufacturers and they
reckon these plugs are actually 50 ohms. So the supplier's insist
they're 75 and the makers say they're 50! I need to know for sure, as
one or the other is in error. How can one tell, by visual inspection
and or physical measurement, which type is which? There must be
something that's visibly different about the two types.

Yes, look at the thickness of the central pin. A 50 Ohm connector has
a central pin of some 1.6mm thick. The 75 Ohm version is a mere needle,
something like 0.8mm.

It's one of my long-time gripes about coaxial connectors that N and
BNC series of the two impedance levels are sufficiently compatible
to mate together, but not enough to do so without damage. In a lab
with someone ignorant of this fact, it's a source of endless trouble.

Jeroen Belleman